Phonograph



June 29, 1937.

E. c. GUEDON PHONOGRAPH Filed Aug. 5;, 193a ZSnventor Gttomeg PnemeaJune' 29,. 1937 UNITED STATES PATENT- OFFICE I 2,085,582 rnoNoGaArnEmile C.-Guedon, Audubon, N. J., assignor to Radio Corporation ofDelaware of America, a corporation Application August 31, 1936, SerialNo. 98,751

7 Claims.

' made in the art of recording and reproducing sound with high fidelity,and-theseadvances'have made it desirable to employ light-weight pick-updevices and light needle pressure on the'reco rds. It has been foundthat various automatic devices under control of the pick-up arm foroperating start. and stop mechanisms or other apparatus at thecompletion of playing of .a record impose aheavy load upon the pick-upneedles causing undue wear on both the needle and the record, andthereby seriously affecting the quality of reproduction. Anotherdisadvantage of many prior art devices of this sort is that they arerelatively noisy and therefore disturbing to the discriminatinglistener, while many of them are also so arranged that they will notoperate unless-and until the needle has reached a predetermined radialposition on the record in proximity to the center thereof. a

' The primary object of my invention is to provide improved mechanismfor automatically controlling the operating condition of a phonograph,which mechanism will be free from the foregoing objections. v Morespecifically, it is an object of my present invention to provideimproved mechanism of the type mentioned which, while under the controlof the pick-up arm or other record scanning member, will not impose anyundue load thereon. Another object of my invention is to provideimproved mechanism as aforesaid which is extremely quiet in operation.

Still another object of my invention is to provide improved mechanism ofthe type set forth which will operate with any, standard record re-'.gardless of the length of the sound groove thereon,

or, in fact, with any type of record which atsom'e magnetic fieldprovided by a suitable magnet as the record is played. As soon, however,as the pick-up arm is actuated by the terminal lead-in or other similargroove of the record, thecore is moved more rapidly and the change influx created thereby through a coil around the magnet produces a currentor voltage which is employed to actuate suitable relay mechanism which,in turn,

operates the phonograph control mechanism.

been

The novel features that I considercharacteristic of my invention are setforth with particularity in the appended claims. The invention itself,however, both as to its organization and method of operation, togetherwith additional objects and advantages thereof, will' best beunderstood: from a description of several embodiments thereof when readin connection with the accompanying drawing in which a Figure 1 is aplan view of one form of my invention,

Figure 2 is a fragmentary side elevation thereof,

'. and

Figure 3 a plan view of a modified form of my invention.

Referring more specifically to the drawing,

wherein similar reference characters designate corresponding partsthroughout, I have shown, in Figs. 1 and 2, a turntable l which supportsa record 3 in operative relation to a' needle 5 of a pick-up device 1carried by a pick-up arm 9, the turntable I being driven by a shaft IIwhich receives'power from a suitablemotor (not shown). The pick-up arm 9is mounted on a post l3 for pivotal movement in a vertical plane and isguided in a horizontal direction along a guide rod' l5 on which abearing or sleeve I1 fixed to the lower end of the post I3 is slidablyreceived.

Extending forwardly from the sleeve I1 is an arm l9 which a second guiderod 2| may assist in supporting, the arm I9 having a core member orarmature 23 of magnetic material fixed to its forward end for movementon a third guide rod 25 across the pole faces of a U-shaped magnet'Z'l.

A coil 29 of conductive material is wound around the magnet 21 and isconnected to a very sensitive relay 3| of any suitable type (forexample, a vacuum tube relay) which is arranged, when ener-' gized, toclose a switch 33 in series with a second and much stronger relay 35which may .be energized from a suitable-source, such as mains 31.

-If desired, a switch 39 may be inserted in circuit with. the coil 28and the relay 3| and a second switch Min circuit with the relays 3| andas for controlling the respective circuits either manually orautomatically.

The relay 35 may be suitably supported, as by a bracket 43 on which arod 45 carrying a sleeve ll of magnetic material is pivotally mounted'ina position to engage an eccentric pin 49 on a mutilated gear 5 I. .Thegear 5| is preferably frictionally coupled toits mounting shaft 53 andisrotatable on the stationary shaft 53 when the'frictional resistanceoffered by the frictional couplingis overcome. mounted on the shaft lltobe continuously rotatable and to"rotate the gear 5| when its teeth.are brought into mesh with the teeth of the gear 55.

A second gear 55 may be rapid movement which creates a change of flux tobe closed, or course.

through the coil 29, and a current or voltage of -sufiicient magnitudeis induced in the coil 29 to actuate the relay 3|, assuming the switch39 The relay 3| then closes the switch 33 which allows the coil "of therelay 35 to be energized if the switch 4| is also closed,-

and the core or armature 36 of the relay 35'then attracts the,sleeve 41and draws the rod toward it a distance sufiicient to enable the free endof the" rod 45 to engage the eccentric pin 49 and impart initialrotation to the gear 5|. This causes the teeth of the gear 5| to meshwith the teeth of the gear whereby it continues to rotate and effect aseries of automatic operations through suitable mechanism immaterial tothe present invention and well known in the prior art, such as removingthe pick-up from the turntable, changing records, and'replacing thepick-up on the new record. The mechanism may be arranged to open theswitch 4lduring the cycle whereby the relay 35 is de-energized and therod 45 reset under the influence of a spring 55, after which the switch4| is again automatically closed. Eventually, during the cycle, the gear5| again reaches the position shown in Fig. 1 and its rotation isstopped by the frictional coupling previously mentioned.

In. the; modification of my invention shown in ture 23 may then be madesomewhat arcuate and the arm l9 considerably shortened to reduce itsweight, and the magnet 21 is placed in the position shown. The operationof this form of theinvention is identical with that previously describedin connection with Fig. 1.

Although I have shown and described but two modifications of ,myinvention, I am fully aware that many other modifications thereof andchanges therein are possible. For example, in place of the permanentmagnet 21, an electromagnet may be usech Also, instead of operatingautomatic phonographi mechanism of the type herein referred-to, therelay 35 may be made to operate brake mechanism or the switch of anelectric driving motor to stop rotation of the turntable. Many 'otherchanges will, no doubt,

readily suggest themselves to those skilled in the art, and I thereforedesire that my invention shall not be limited except insofar as isnecessitated by theprior art and by the spirit of the appended claims. Iclaim as my invention:

1. In a phonograph, the combination of a scanning member movable overa-record, means for automatically controlling the operating condition ofthe phonograph, means including asource.

of flux for rendering said first named means operative to alter theoperatingacondition of the phonograph, and means movable with saidscanning member and operable to affect the fiux upon a change in therate of movement of said scanning member over. the record whereby torender said first named means operative.

2. In a phonograph, the combination of a record scanning member movableover a record, means for automatically controlling the operatingcondition of the phonograph, a source of magnetic flux, means associatedwith said fiux source for rendering said first named means operative toalter the operating condition of the phonograph, and means movable withsaid scanning member and operable to affect the flux upon a change inthe rate of movement of said scanning member over the record whereby toenergize said second named means and cause' the latter to render saidfirst named means operative.

3. In a phonograph, thecombination of a record scanning member movableover a record, means for automatically controlling the operatingcondition ofthe phonograph, a source of magnetic flux, a coil of.conductive material associated with said source, means associated withsaid coil adapted to render said control means operative to alter theoperating condition of the phonograph, and an armature coupled to andmovable in response to said scanning member.

through said flux, said armature being effective, upon a change in therate of movement of said scanning member over the record, to create achange of flux through said coil whereby to induce a. current thereinfor energizing said second namedmeans.

4. -In a phonograph, the combination of a scanning member movable over arecord, means for automatically controlling the operating condition ofthe phonograph, a permanent magnet, a coil of conductive material aroundsaid magnet, means associated with said coil adapted to render saidcontrol means operative to alter the operating condition of thephonograph, and an armature coupled to said scanning member, saidarmature being arranged to be moved by said scanning faces of saidmagnet.

6. The invention set forth in claim 4 characterized in that the meansassociated with said coil for rendering the control means operativeincludes a sensitive relay adapted to be operated by the current inducedin said coil.

7. The invention set forth in claim 4 characterized in that the meansassociated with said

